In conventional frame building construction, there is frequently provided a soffit which extends substantially horizontally from the outer wall of such building to the outer edges of its eaves. There is also normally provided between the lower surface of the roof of such building and the upper edge of the wall thereof passages between the roof rafters which provide communication between a first zone immediately under the roof thereof and a second zone defined between the projecting eaves and the soffit. This communication permits at least a small amount of outside air to move into the zone between the eaves and the soffit and to move from that zone into the zone under the roof. Also, there is or are provided one or more ventilating openings near the peak of the roof for allowing relatively warm air to escape. Thus, in cold weather, relatively warm air that rises toward the peak of the roof can become mixed with cooler outside air that flows through the passages, thereby to maintain a more uniform cooler temperature across the entire width of the roof. However, when the buiding is insulated by placing a layer of insulation on top of the ceiling of whatever living space is provided below the zone immediately under such roof, these openings are often blocked and outside air is no longer permitted to flow from the zone between the eaves and soffit into the zone directly under the roof. Thus, in cold weather, because room heat that flows upwardly through the insulation tends to accumulate toward the peak of the roof, melting of snow will occur thereat, such melted snow will flow down along the roof and will often freeze as it reaches the outer edge of the eaves which are unheated. Consequently a ridge of ice builds up along the eaves and as subsequent melting occurs, the thawed ice on the eaves often flows back under the shingles of said roof and causes leakage through the ceiling above mentioned and/or into the inside of the building wall.
This problem is well known and has long been recognized and numerous devices have been provided in an attempt to correct same. One particularly common means for accomplishing this purpose is to provide a resistance heating wire along the edge of said eaves, or a resistance wire describing a circuitous pattern immediately back from the edge of such eaves, in order to prevent the formation of ice thereon. This system works well but it is both expensive to install and requires the constant use during cold weather of a substantial amount of electrical energy.
Other means have also been provided but insofar as I am aware, they have all either been even more expensive to install and/or operate than the resistance wire means above-mentioned or they have been insufficiently effective to be satisfactory.
Accordingly, the objects of the invention include:
1. To provide means for preventing insulation installed above a ceiling from blocking air flow between a first zone under said roof and a second zone between the projecting eaves of such building and a soffit associated therewith, so that cool outside air can flow into said first zone to maintain the roof at a more uniform cooler temperature across its entire width in order to minimize melting of snow thereon.
2. To provide means, as aforesaid, for maintaining a channel of air flow communication past insulation between said first zone and said second zone.
3. To provide inexpensive means, as aforesaid, which may be installed between roof rafters during the application of ceiling insulation for preventing such insulation from blocking air flow communication between said first and second zones but instead insuring a continuous channel of air flow communication therebetween.
4. To provide a device, as aforesaid, which will be sufficiently inexpensive as not to add materially to the cost of the insulation job.
5. To provide a device, as aforesaid, which can be installed readily and quickly by simple means and at the same time as the insulation and will thereby not add materially if at all to the labor cost of an insulation job.
6. To provide a device, as aforesaid which will easily last as long as the insulation and/or the building and hence not require repair or renewal during the normal life of either the insulation or of the building.
7. To provide a device, as aforesaid, wherein the manner of installation can be readily explained to workmen installing such insulation and which will not require special equipment or tools for the installation of such device.
8. To provide a device, as aforesaid, which can be installed as required by means of the same tools as utilized for installing the insulation.
Other purposes and objects of the invention will be apparent to persons acquainted with devices of this general type upon reading the following specification and inspection of the accompanying drawings.